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    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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    <style>
        div span:nth-of-type(2){
            color: blue;
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        div span:nth-child(2){
            background-color: brown;
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        tr >td:not(:nth-child(odd)){
            background-color: chartreuse;
        }
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    <div>
        <span>第一个span</span>
        <span>第五个span</span>
        <div>
            <span>第二个span</span>
            <span>第四个span</span>
        </div>
        <p>第一个p</p>
        <span>第三个span</span>
    </div>


    <table border="1">
        <tr>
          <td>houdunren.com</td>
          <td>hdcms.com</td>
          <td>后盾人</td>
          <td>houdunwang.com</td>
          <td>hdcms</td>
        </tr>
</body>
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